A fluorescent lamp (FL) has a high efficiency in emitting light. Thus, in order to use the FL lamp instead of a incandescent lamp, a size of the FL lamp is made to be small. Trying to insert the small fluorescent lamp or the like into a bulb socket of the incandescent lamp results in further reduction of the lamp apparatus size including an electronic ballast.
FIG. 2 shows a conventional compact fluorescent lamp apparatus having a ballast 22 without a compact fluorescent lamp socket, a small fluorescent lamp 23 and a bulb base 21, which are integrated in one unit.
However, although the small lamp apparatus is convenient to use, both the socket and ballast are to be replaced with a new one in case where a life of a fluorescent lamp is ended, therefore causing a source of waste material.
As shown in FIG. 3, a compact fluorescent lamp has been commercially available which has a plug that can be inserted into a socket in a socket-type ballast so as not to waste the materials.
For the compact fluorescent lamp, many types of ballast are produced. One such type of electronic ballast has a socket for accommodating the compact fluorescent lamp, and an incandescent bulb base for connection to an incandescent socket.
However, a size of the conventional electronic ballast having a compact fluorescent lamp socket and a bulb base is large and inconvenient for use.